#include <stdio.h>
#include <string.h>


int main()
{
    int n;
    char arr[1001];
    scanf("%d",&n);
    n%=26;
    scanf("%s",arr);

    int len = strlen(arr);
    for (int i = 0;i < len;i++)
    {
        int temp = arr[i]-'a';
        int res = (temp+n)%26;
        arr[i] = res+'a';
    }

    printf("%s\n",arr);
    switch (expression)
    {
    case constant expression:
        /* code */
        break;
    
    default:
        break;
    }
    return 0;
}